It is secure, at least if comparing to emails.
Before email came into popularity, fax transmissions presented the only way to send written communication quickly. They could provide papers and printouts in a few short minutes over hundreds or thousands of miles. Since email has come into wide use, some companies have completely abandoned fax machines. Still, faxes hold some advantages over email communication.
Since fax transmissions use paper and email does not, problems with the paper put fax communication at a disadvantage. Like printers, fax machines can experience paper jams. Unlike printers, these paper jams can occur in one of two machines needed to complete a fax transmission. The original document can jam in the sending fax machine, possibly rendering the document unusable if the jam is severe enough. On the receiving end, the paper being printed on can jam in the fax machine, disrupting the whole process. The receiving machine could also run out of the paper, and the user on that end may not realize the paper is gone for some time. This delay could cause time-sensitive communications to go unanswered for hours or even days.
One Step Process
One of the biggest strengths of fax transmissions occurs when a person is dealing with a signed document or a document that only exists in hard copy. If that person wants to send the document in an email, he needs to image the document with a scanner or multifunction printer. The user then has to edit the scanned image before choosing a spot on the computer’s hard drive to save the scanned document. When the person sends the email, the scan file must be attached to the email. In contrast, a person using a fax machine merely places the document in the machine and hits a few keys to send it to the receiving party.
Documents sent by email can be edited by a user, whereas documents sent by fax cannot. In situations where the two parties are collaborating on a project, the ability to edit the document helps facilitate that collaboration, giving both users the ease of making changes quickly. If the two parties are engaged in an adversarial relationship, a fax transmission may be more attractive. The nature of the hard-copy fax document makes altering the document to defame or manipulate the other party more difficult.
Many computers and printers today can send both faxes and email. This means that digital files can be sent from a computer to a fax machine, where it is delivered as a hard copy document. These computers and printers can also receive fax transmissions from fax machines, providing the advantages of both fax and email.
But if you don't have one of those big and expensive fax machines, consider using an online fax service instead, you might like that better.